package com.xxl.job.core.util;

import com.xxl.job.core.context.XxlJobHelper;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * 1、内嵌编译器如"PythonInterpreter"无法引用扩展包，因此推荐使用java调用控制台进程方式"Runtime.getRuntime().exec()"来运行脚本(shell或python)；
 * 2、因为通过java调用控制台进程方式实现，需要保证目标机器PATH路径正确配置对应编译器；
 * 3、暂时脚本执行日志只能在脚本执行结束后一次性获取，无法保证实时性；因此为确保日志实时性，可改为将脚本打印的日志存储在指定的日志文件上； 4、python
 * 异常输出优先级高于标准输出，体现在Log文件中，因此推荐通过logging方式打日志保持和异常信息一致；否则用prinf日志顺序会错乱
 * <p>
 * Created by xuxueli on 17/2/25.
 */
public class ScriptUtil {

	/**
	 * make script file
	 * @param scriptFileName
	 * @param content
	 * @throws IOException
	 */
	public static void markScriptFile(String scriptFileName, String content) throws IOException {
		// make file, filePath/gluesource/666-123456789.py
		try (FileOutputStream fileOutputStream = new FileOutputStream(scriptFileName)) {
			fileOutputStream.write(content.getBytes(StandardCharsets.UTF_8));
		}
	}

	/**
	 * 脚本执行，日志文件实时输出
	 * @param command
	 * @param scriptFile
	 * @param logFile
	 * @param params
	 * @return
	 */
	public static int execToFile(String command, String scriptFile, String logFile, String... params) {

		FileOutputStream fileOutputStream = null;
		Thread inputThread = null;
		Thread errThread = null;
		try {
			// file
			fileOutputStream = new FileOutputStream(logFile, true);

			// command
			List<String> cmdarray = new ArrayList<>();
			cmdarray.add(command);
			cmdarray.add(scriptFile);
			if (params != null) {
				cmdarray.addAll(Arrays.asList(params));
			}
			String[] cmdarrayFinal = cmdarray.toArray(new String[0]);

			// process-exec
			final Process process = Runtime.getRuntime().exec(cmdarrayFinal);

			// log-thread
			final FileOutputStream finalFileOutputStream = fileOutputStream;
			inputThread = new Thread(() -> {
				try {
					copy(process.getInputStream(), finalFileOutputStream, new byte[1024]);
				}
				catch (IOException e) {
					XxlJobHelper.log(e);
				}
			});
			errThread = new Thread(() -> {
				try {
					copy(process.getErrorStream(), finalFileOutputStream, new byte[1024]);
				}
				catch (IOException e) {
					XxlJobHelper.log(e);
				}
			});
			inputThread.start();
			errThread.start();

			// process-wait
			int exitValue = process.waitFor(); // exit code: 0=success, 1=error

			// log-thread join
			inputThread.join();
			errThread.join();

			return exitValue;
		}
		catch (Exception e) {
			XxlJobHelper.log(e);
			return -1;
		}
		finally {
			if (fileOutputStream != null) {
				try {
					fileOutputStream.close();
				}
				catch (IOException e) {
					XxlJobHelper.log(e);
				}

			}
			if (inputThread != null && inputThread.isAlive()) {
				inputThread.interrupt();
			}
			if (errThread != null && errThread.isAlive()) {
				errThread.interrupt();
			}
		}
	}

	/**
	 * 数据流Copy（Input自动关闭，Output不处理）
	 * @param inputStream
	 * @param outputStream
	 * @param buffer
	 * @return
	 * @throws IOException
	 */
	private static long copy(InputStream inputStream, OutputStream outputStream, byte[] buffer) throws IOException {
		try {
			long total = 0;
			for (;;) {
				int res = inputStream.read(buffer);
				if (res == -1) {
					break;
				}
				if (res > 0) {
					total += res;
					if (outputStream != null) {
						outputStream.write(buffer, 0, res);
					}
				}
			}
			outputStream.flush();
			// out = null;
			inputStream.close();
			inputStream = null;
			return total;
		}
		finally {
			if (inputStream != null) {
				inputStream.close();
			}
		}
	}

}
